Quantum Matter Institute, The University of British Columbia, Canada

Abstract:

Until now, insulating spin chain systems have predominated in research. Here, we investigate a new metallic compound Ti4MnBi2 using neutron scattering and first-principles density-functional theory. We observed remarkably distinctive signals: a gapped magnetic excitation continuum exclusively dispersing along the chain around the Brillouin-zone center down to 0.3K, and a temperature-induced gapless excitation continuum, suggesting elementary excitations as fractional spin S = 1/2 spinons and solitons. Moreover, μSR data reveals the absence of correlated long-range magnetic order down to 0.015K, providing evidence for the existence of a quantum spin liquid state. The fundamental physics can be elucidated through an orbital dimer featuring up-up-down-down spin chains. Our results shed light on the study of novel quantum spin dynamics in Ising-like metallic spin chains.

Introduction to the Speaker：

Xiyang is a PostDoc at the Stewart Blusson Quantum Matter Institute, University of British Columbia (UBC). He earned his Ph.D. in 2019 from IOP, CAS. Initially, he was a PostDoc at CityU of Hong Kong before relocating to UBC, Canada. His Ph.D. work predominantly employed neutron scattering to investigate phonon properties in amorphous and thermoelectric materials. Presently, his focus lies in atomic dynamics within disordered materials and spin dynamics in frustrated, low-dimensional quantum magnets. Specifically, his investigation into spin dynamics in 1D magnets utilizes neutron scattering and μSR techniques, supplemented by analyzing transport and magnetic properties using MPMS and PPMS measurements. Xiyang's contributions include 14 published papers, including PRL, NC, AM, and others. He is also a referee for esteemed journals such as PRL, NC, PRB, and Scripta Materialia.

联系人：王芳卫 研究员 (82648078，fwwang@iphy.ac.cn )